This invention relates to a semiconductor integrated circuit device with .a self-test function.
A large scale integrated circuit (LSI) and a test circuit which operates independently of the LSI are formed on a semiconductor chip. The test circuit is used to test the function of the LSI according to the self-test program. A signature register is generally used as the self-test circuit.
An application system with LSIs is also provided with a self-test program. At the time of power on, the system functions and the LSIs functions are tested by the self-test programs.
The LSIs and the system are independently tested. Therefore, even if some of the LSI test functions are the same as those in the application system test functions, it is impossible to apply those of the LSI test functions for the application system function test. Therefore, the self-test program for the application system cannot be shortened, and much labor and time are needed to form the program.